Results 31 to 40 of about 301,064 (245)

Constraining dust properties in circumstellar envelopes of C-stars in the Magellanic Clouds: Optical constants and grain size of carbon dust [PDF]

Proceedings of the International Astronomical Union, 2016
We present a new approach aimed at constraining the typical size and optical properties of carbon dust grains in Circumstellar envelopes (CSEs) of carbon-rich stars (C-stars) in the Small Magellanic Cloud (SMC).
A. Nanni, P. Marigo, M. Groenewegen, B. Aringer, S. Rubele, A. Bressan, L. Girardi, G. Pastorelli, S. Bladh   +8 more
semanticscholar   +1 more source

Kinetics of the tautomerization of thioimidic acids R−C(SH)NH → R−C(S)NH2: For R = H, F, HO, CN, NC, H2N, HC(O), HC(S), HC≡ C, CH3, CF3, H2C=CH, HOCH2, H2NCH2,CH3C(O), C2H5, (CH3)2CH, C6H5

International Journal of Chemical Kinetics, Volume 55, Issue 11, Page 731-742, November 2023., 2023
Abstract The kinetics of the tautomerization of thio‐imidic acids RC(SH)NH were determined at low (50–300 K) and high (500–1500 K) temperatures as R was varied to encompass mono‐ and diatomic species H, F, HO, NC, CN through H2N, HC(O), HC(S), HC≡ C, H3C, F3C, HOCH2, H2C=CH, CH3C(O), H2NCH2 and including ethyl, isopropyl and phenyl groups. The presence
Judith Würmel, John M. Simmie
wiley   +1 more source

Insights Into the Gas-Phase Structure and Internal Dynamics of Diphenylsilane: A Broadband Rotational Spectroscopy Study. [PDF]

Chemphyschem
The structure of diphenylsilane could be determined from the rotational spectra of all its singly substituted heavy atom isotopologues. A comparison with its oxygen analogue diphenylether revealed some interesting differences in the internal dynamics as well as in the gas‐phase structure.
Batra G, Schnell M.
europepmc   +2 more sources

Lutidyl Radical Photoelectron Spectra Reveal Additive Substituent Effects on Benzyl Derivatives’ Ionization Energy

ChemPhysChem, Volume 24, Issue 20, October 17, 2023., 2023
Threshold photoelectron spectroscopy with vacuum ultraviolet synchrotron radiation and quantum chemical calculations shed new light on the ionization energies of xylyl, picolyl and lutidyl radicals. N‐ and CH3‐substituent effects on the ionization energies of benzyl‐type reactive intermediates are found to be position‐dependent and additive.
Keisuke Kanayama, Christin Fernholz, Hisashi Nakamura, Kaoru Maruta, Andras Bodi, Patrick Hemberger   +5 more
wiley   +1 more source

Microlensing of circumstellar envelopes: II. emission lines from radial and azimuthal flow during fold caustic crossings [PDF]

, 2003
This paper examines the line profile evolution due to bulk motion in circumstellar envelopes during microlensing fold caustic crossing events. These events have recently been shown to be a sensitive probe of stellar surface brightness profiles, thus ...
Bryce, H.M., Hendry, M.A., Ignace, R.
core   +1 more source

Interferometric view of the circumstellar envelopes of northern FU Orionis-type stars [PDF]

, 2017
FU Orionis-type objects are young, low-mass stars with large outbursts in visible light that last for several years or decades. They are thought to represent an evolutionary phase during the life of every young star when accretion from the circumstellar ...
O. Feh'er, 'A. K'osp'al, P. 'Abrah'am, M. Hogerheijde, C. Brinch   +4 more
semanticscholar   +1 more source

The Chemistry of the Cyaphide Ion

Angewandte Chemie International Edition, Volume 62, Issue 32, August 7, 2023., 2023
128 years after the erroneously assumed synthesis of sodium cyaphide, Na(CP), and 51 years after the definitive proof of the existence of HCP, the chemistry of the cyaphide anion has finally gained momentum. This review summarizes the chemistry of the cyaphide anion, (C≡P)−, from its beginnings to the state‐of‐the art.
Tim Görlich, Peter Coburger, Eric S. Yang, Jose M. Goicoechea, Hansjörg Grützmacher, Christian Müller   +5 more
wiley   +1 more source

Water isotopologues in the circumstellar envelopes of M-type AGB stars [PDF]

, 2017
AIM: In this study we examine rotational emission lines of two isotopologues of water: H$_2$$^{17}$O and H$_2$$^{18}$O. By determining the abundances of these molecules, we aim to use the derived isotopologue --- and hence oxygen isotope --- ratios to ...
T. Danilovich, R. Lombaert, L. Decin, A. Karakas, A. Karakas, M. Maercker, H. Olofsson   +6 more
semanticscholar   +1 more source

Vibrational Predissociation Spectra of C2N− and C3N−: Bending and Stretching Vibrations

ChemPhysChem, Volume 24, Issue 15, August 1, 2023., 2023
Infrared predissociation spectra of C2N−(H2) and C3N−(H2) is reported using a cryogenic ion trap at the FELIX Laboratory, thus allowing the detection of low‐lying bending and stretching vibrations of both anions simultaneously. Vibrational configuration interaction calculations validate the assignment.
Franziska Dahlmann, Dennis F. Dinu, Pavol Jusko, Christine Lochmann, Thomas Gstir, Aravindh N. Marimuthu, Klaus R. Liedl, Sandra Brünken, Roland Wester   +8 more
wiley   +1 more source

Theory of circumstellar envelopes [PDF]

Symposium - International Astronomical Union, 1987
After a comparison of conventional photospheres with circumstellar envelopes the radiation in spherical shells is considered. We discuss the transfer equation and a new quasi-exact solution in term of the transition matrix-Various methods used for the numerical evaluation of the specific intensities are summarized.
openaire   +1 more source